Signaling system number 7 (SS7) is widely used as the signaling protocol in telecommunication networks. Each SS7 message is assigned one of four congestion priorities, which may be used to determine how each message is handled based on the current capacity of each signaling route. Typically, user messages, such as those for call setup and teardown, are assigned a lower priority than network management messages.
In converged networks, portions of the network use the Internet protocol (IP) to transport signaling messages, while other portions of the network use SS7 to transport signaling messages. For example, IP may be used for message transfer between signal transfer points (STP) in the network, and SS7 may be used to communicate with endpoints, or vice-versa. In one implementation, an STP may receive an SS7 message from a service switching point (SSP), encapsulate the SS7 message in an IP packet, and transfer the received SS7 message to another STP using IP. However, once the SS7 message is encapsulated in an IP packet, the priority level of the SS7 message cannot be determined by examining the IP packet header. In the event that the IP network becomes congested, the delivery of high priority SS7 messages may be delayed since all IP encapsulated SS7 messages may be treated with the same priority level.
In addition, most SS7 user messages are considered low priority and are treated the same. However, users may wish to ensure that their messages are handled in a timely fashion, especially when the network is experiencing abnormal conditions, such as congestion. While a user may be willing to pay for preferred service, there is currently no provision to enable tiers of service in an SS7/IP network.
Accordingly, there is a need to provide a system and method to assign a priority to an IP packet based on the priority of the SS7 message that is encapsulated in the packet.
There is also a need to provide a system and method to indicate a desired level of service for an SS7 user message and reflect the desired level of service in the IP packet in which the SS7 user message is encapsulated.